1,样例说明

(1)在没有鼠标介入的情况下,这些球就像有磁性一样拼成“Google”字样。
(2)在鼠标移动到其中后,小球像是受到了排斥,向画布的四周扩散,然后不规则地反弹回来。

原文出自:www.hangge.com  转载请保留原文链接:http://www.hangge.com/blog/cache/detail_1059.html

2.源码:

<!DOCTYPE HTML>

<html>
  <head>
    <style>
      body {
        margin: 0px;
        padding: 0px;
      }
      canvas {
        cursor: pointer;
        border: 1px solid black;
        margin:20px 20px 20px 20px;
    }
    </style>
  </head>
  <body>
    <canvas id="myCanvas" width="578" height="200"></canvas>
    <script>
      window.requestAnimFrame = (function(callback) {
        return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
        function(callback) {
          window.setTimeout(callback, 1000 / 60);
        };
      })();
 
      function initBalls() {
        balls = [];
 
        var blue = '#3A5BCD';
        var red = '#EF2B36';
        var yellow = '#FFC636';
        var green = '#02A817';
 
        // G
        balls.push(new Ball(173, 63, 0, 0, blue));
        balls.push(new Ball(158, 53, 0, 0, blue));
        balls.push(new Ball(143, 52, 0, 0, blue));
        balls.push(new Ball(130, 53, 0, 0, blue));
        balls.push(new Ball(117, 58, 0, 0, blue));
        balls.push(new Ball(110, 70, 0, 0, blue));
        balls.push(new Ball(102, 82, 0, 0, blue));
        balls.push(new Ball(104, 96, 0, 0, blue));
        balls.push(new Ball(105, 107, 0, 0, blue));
        balls.push(new Ball(110, 120, 0, 0, blue));
        balls.push(new Ball(124, 130, 0, 0, blue));
        balls.push(new Ball(139, 136, 0, 0, blue));
        balls.push(new Ball(152, 136, 0, 0, blue));
        balls.push(new Ball(166, 136, 0, 0, blue));
        balls.push(new Ball(174, 127, 0, 0, blue));
        balls.push(new Ball(179, 110, 0, 0, blue));
        balls.push(new Ball(166, 109, 0, 0, blue));
        balls.push(new Ball(156, 110, 0, 0, blue));
 
        // O
        balls.push(new Ball(210, 81, 0, 0, red));
        balls.push(new Ball(197, 91, 0, 0, red));
        balls.push(new Ball(196, 103, 0, 0, red));
        balls.push(new Ball(200, 116, 0, 0, red));
        balls.push(new Ball(209, 127, 0, 0, red));
        balls.push(new Ball(223, 130, 0, 0, red));
        balls.push(new Ball(237, 127, 0, 0, red));
        balls.push(new Ball(244, 114, 0, 0, red));
        balls.push(new Ball(242, 98, 0, 0, red));
        balls.push(new Ball(237, 86, 0, 0, red));
        balls.push(new Ball(225, 81, 0, 0, red));
 
        // O
        var oOffset = 67;
        balls.push(new Ball(oOffset + 210, 81, 0, 0, yellow));
        balls.push(new Ball(oOffset + 197, 91, 0, 0, yellow));
        balls.push(new Ball(oOffset + 196, 103, 0, 0, yellow));
        balls.push(new Ball(oOffset + 200, 116, 0, 0, yellow));
        balls.push(new Ball(oOffset + 209, 127, 0, 0, yellow));
        balls.push(new Ball(oOffset + 223, 130, 0, 0, yellow));
        balls.push(new Ball(oOffset + 237, 127, 0, 0, yellow));
        balls.push(new Ball(oOffset + 244, 114, 0, 0, yellow));
        balls.push(new Ball(oOffset + 242, 98, 0, 0, yellow));
        balls.push(new Ball(oOffset + 237, 86, 0, 0, yellow));
        balls.push(new Ball(oOffset + 225, 81, 0, 0, yellow));
 
        // G
        balls.push(new Ball(370, 80, 0, 0, blue));
        balls.push(new Ball(358, 79, 0, 0, blue));
        balls.push(new Ball(346, 79, 0, 0, blue));
        balls.push(new Ball(335, 84, 0, 0, blue));
        balls.push(new Ball(330, 98, 0, 0, blue));
        balls.push(new Ball(334, 111, 0, 0, blue));
        balls.push(new Ball(348, 116, 0, 0, blue));
        balls.push(new Ball(362, 109, 0, 0, blue));
        balls.push(new Ball(362, 94, 0, 0, blue));
        balls.push(new Ball(355, 128, 0, 0, blue));
        balls.push(new Ball(340, 135, 0, 0, blue));
        balls.push(new Ball(327, 142, 0, 0, blue));
        balls.push(new Ball(325, 155, 0, 0, blue));
        balls.push(new Ball(339, 165, 0, 0, blue));
        balls.push(new Ball(352, 166, 0, 0, blue));
        balls.push(new Ball(367, 161, 0, 0, blue));
        balls.push(new Ball(371, 149, 0, 0, blue));
        balls.push(new Ball(366, 137, 0, 0, blue));
 
        // L
        balls.push(new Ball(394, 49, 0, 0, green));
        balls.push(new Ball(381, 50, 0, 0, green));
        balls.push(new Ball(391, 61, 0, 0, green));
        balls.push(new Ball(390, 73, 0, 0, green));
        balls.push(new Ball(392, 89, 0, 0, green));
        balls.push(new Ball(390, 105, 0, 0, green));
        balls.push(new Ball(390, 118, 0, 0, green));
        balls.push(new Ball(388, 128, 0, 0, green));
        balls.push(new Ball(400, 128, 0, 0, green));
 
        // E
        balls.push(new Ball(426, 101, 0, 0, red));
        balls.push(new Ball(436, 98, 0, 0, red));
        balls.push(new Ball(451, 95, 0, 0, red));
        balls.push(new Ball(449, 83, 0, 0, red));
        balls.push(new Ball(443, 78, 0, 0, red));
        balls.push(new Ball(430, 77, 0, 0, red));
        balls.push(new Ball(418, 82, 0, 0, red));
        balls.push(new Ball(414, 93, 0, 0, red));
        balls.push(new Ball(412, 108, 0, 0, red));
        balls.push(new Ball(420, 120, 0, 0, red));
        balls.push(new Ball(430, 127, 0, 0, red));
        balls.push(new Ball(442, 130, 0, 0, red));
        balls.push(new Ball(450, 125, 0, 0, red));
 
        return balls;
      }
      function getMousePos(canvas, evt) {
        // get canvas position
        var obj = canvas;
        var top = 0;
        var left = 0;
        while(obj.tagName != 'BODY') {
          top += obj.offsetTop;
          left += obj.offsetLeft;
          obj = obj.offsetParent;
        }
 
        // return relative mouse position
        var mouseX = evt.clientX - left + window.pageXOffset;
        var mouseY = evt.clientY - top + window.pageYOffset;
        return {
          x: mouseX,
          y: mouseY
        };
      }
      function updateBalls(canvas, balls, timeDiff, mousePos) {
        var context = canvas.getContext('2d');
        var collisionDamper = 0.3;
        var floorFriction = 0.0005 * timeDiff;
        var mouseForceMultiplier = 1 * timeDiff;
        var restoreForce = 0.002 * timeDiff;
 
        for(var n = 0; n < balls.length; n++) {
          var ball = balls[n];
          // set ball position based on velocity
          ball.y += ball.vy;
          ball.x += ball.vx;
 
          // restore forces
          if(ball.x > ball.origX) {
            ball.vx -= restoreForce;
          }
          else {
            ball.vx += restoreForce;
          }
          if(ball.y > ball.origY) {
            ball.vy -= restoreForce;
          }
          else {
            ball.vy += restoreForce;
          }
 
          // mouse forces
          var mouseX = mousePos.x;
          var mouseY = mousePos.y;
 
          var distX = ball.x - mouseX;
          var distY = ball.y - mouseY;
 
          var radius = Math.sqrt(Math.pow(distX, 2) + Math.pow(distY, 2));
 
          var totalDist = Math.abs(distX) + Math.abs(distY);
 
          var forceX = (Math.abs(distX) / totalDist) * (1 / radius) * mouseForceMultiplier;
          var forceY = (Math.abs(distY) / totalDist) * (1 / radius) * mouseForceMultiplier;
 
          if(distX > 0) {// mouse is left of ball
            ball.vx += forceX;
          }
          else {
            ball.vx -= forceX;
          }
          if(distY > 0) {// mouse is on top of ball
            ball.vy += forceY;
          }
          else {
            ball.vy -= forceY;
          }
 
          // floor friction
          if(ball.vx > 0) {
            ball.vx -= floorFriction;
          }
          else if(ball.vx < 0) {
            ball.vx += floorFriction;
          }
          if(ball.vy > 0) {
            ball.vy -= floorFriction;
          }
          else if(ball.vy < 0) {
            ball.vy += floorFriction;
          }
 
          // floor condition
          if(ball.y > (canvas.height - ball.radius)) {
            ball.y = canvas.height - ball.radius - 2;
            ball.vy *= -1;
            ball.vy *= (1 - collisionDamper);
          }
 
          // ceiling condition
          if(ball.y < (ball.radius)) {
            ball.y = ball.radius + 2;
            ball.vy *= -1;
            ball.vy *= (1 - collisionDamper);
          }
 
          // right wall condition
          if(ball.x > (canvas.width - ball.radius)) {
            ball.x = canvas.width - ball.radius - 2;
            ball.vx *= -1;
            ball.vx *= (1 - collisionDamper);
          }
 
          // left wall condition
          if(ball.x < (ball.radius)) {
            ball.x = ball.radius + 2;
            ball.vx *= -1;
            ball.vx *= (1 - collisionDamper);
          }
        }
      }
      function Ball(x, y, vx, vy, color) {
        this.x = x;
        this.y = y;
        this.vx = vx;
        this.vy = vy;
        this.color = color;
        this.origX = x;
        this.origY = y;
        this.radius = 10;
      }
      function animate(canvas, balls, lastTime, mousePos) {
        var context = canvas.getContext('2d');
 
        // update
        var date = new Date();
        var time = date.getTime();
        var timeDiff = time - lastTime;
        updateBalls(canvas, balls, timeDiff, mousePos);
        lastTime = time;
 
        // clear
        context.clearRect(0, 0, canvas.width, canvas.height);
 
        // render
        for(var n = 0; n < balls.length; n++) {
          var ball = balls[n];
          context.beginPath();
          context.arc(ball.x, ball.y, ball.radius, 0, 2 * Math.PI, false);
          context.fillStyle = ball.color;
          context.fill();
        }
 
        // request new frame
        requestAnimFrame(function() {
          animate(canvas, balls, lastTime, mousePos);
        });
      }
      var canvas = document.getElementById('myCanvas');
      var balls = initBalls();
      var date = new Date();
      var time = date.getTime();
      /*
       * set mouse position really far away
       * so the mouse forces are nearly obsolete
       */
      var mousePos = {
        x: 9999,
        y: 9999
      };
 
      canvas.addEventListener('mousemove'function(evt) {
        var pos = getMousePos(canvas, evt);
        mousePos.x = pos.x;
        mousePos.y = pos.y;
      });
 
      canvas.addEventListener('mouseout'function(evt) {
        mousePos.x = 9999;
        mousePos.y = 9999;
      });
      animate(canvas, balls, time, mousePos);
 
    </script>
  </body>
</html>

HTML5 - Canvas动画样例(谷歌弹跳球)的更多相关文章

  1. [js高手之路]html5 canvas动画教程 - 边界判断与小球粒子模拟喷泉,散弹效果

    备注:本文后面的代码,如果加载了ball.js,那么请使用这篇文章[js高手之路] html5 canvas动画教程 - 匀速运动的ball.js代码. 本文,我们要做点有意思的效果,首先,来一个简单 ...

  2. 7 个顶级的 HTML5 Canvas 动画赏析

    HTML5确实是一项改革浏览器乃至整个软件行业的新技术,它可以帮助我们Web开发者很方便地在网页上实现动画特效,而无需臃肿的Flash作为支撑.本文分享7个顶级的HTML5 Canvas 动画,都有非 ...

  3. 8个经典炫酷的HTML5 Canvas动画欣赏

    HTML5非常强大,尤其是Canvas技术的应用,让HTML5几乎可以完成所有Flash能完成的效果.本文精选了8个经典炫酷的HTML5 Canvas动画欣赏,每一个都提供全部的源代码,希望对你有所帮 ...

  4. 7个惊艳的HTML5 Canvas动画效果及源码

    HTML5非常强大,尤其是现在大部分浏览器都支持HTML5和CSS3,用HTML5制作的动画也多了起来.另外,Canvas上绘制图形非常简单,本文就分享了一些强大的HTML5 Cnavas动画,一起来 ...

  5. Html5 Canvas动画旋转的小方块;

    <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta http ...

  6. HTML5 Canvas动画效果演示

    HTML5 Canvas动画效果演示 主要思想: 首先要准备一张有连续帧的图片,然后利用HTML5 Canvas的draw方法在不同的时间 间隔绘制不同的帧,这样看起来就像动画在播放. 关键技术点: ...

  7. HTML5 Canvas动画效果演示 - 流浪的鱼 - 博客频道 - CSDN.NET

    HTML5 Canvas动画效果演示 - 流浪的鱼 - 博客频道 - CSDN.NET HTML5 Canvas动画效果演示

  8. HTML5 Canvas动画效果实现原理

    在线演示 使用HTML5画布可以帮助我们高速实现简单的动画效果.基本原理例如以下: 每隔一定时间绘制图形而且清除图形,用来模拟出一个动画过程,能够使用context.clearRect(0, 0, x ...

  9. [js高手之路]html5 canvas动画教程 - 边界判断与反弹

    备注:本文后面的代码,如果加载了ball.js,那么请使用这篇文章[js高手之路] html5 canvas动画教程 - 匀速运动的ball.js代码. 边界反弹: 当小球碰到canvas的四个方向的 ...

随机推荐

  1. NumPy基础:数组和矢量计算

    今天被老板fire了,还是继续抄书吧,安抚我受伤的小心脏.知识还是得慢慢积累,一步一个脚印,这样或许才是最快的捷径. ------2015-2-16-------------------------- ...

  2. 最小点集覆盖/HDU2119

    题目连接 先试一下题/?/ 最小点集覆盖=最大匹配 /*根据i.j建图,跑一边最大匹配 */ #include<cstdio> #include<cstring> using ...

  3. 添加以及删除className

    <!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content ...

  4. Linux学习 -- Shell编程 -- 正则表达式

    正则表达式与通配符 正则 -- 匹配字符串 -- 包含匹配     grep.awk.sed等 通配符 -- 匹配文件名 -- 完全匹配  ls.find.cp等 基础正则表达式

  5. codeforces 558/C Amr and Chemistry(数论+位运算)

    题目链接:http://codeforces.com/problemset/problem/558/C 题意:把n个数变成相同所需要走的最小的步数易得到结论,两个奇数不同,一直×2不可能有重叠枚举每个 ...

  6. python 从windows上传文件到linux脚本

    import paramiko import datetime import os hostname = '192.168.112.132' username = 'root' password = ...

  7. 【linux系统学习】计算机硬件核心知识

    (一)企业里PC服务器品牌及型号 互联网公司服务器品牌:DELL,HP,IBM(百度):国内品牌:浪潮,联想,航天联志 DELL服务器品牌:1u = 4.45CM 2010年前 1u 1850,195 ...

  8. 如何延长zencart1.5后台的登录时间而不退出

    2012-12-25 使用过zencart1.5版本的人都知道,后台登陆后,如果没有任何操作的话最长15分钟后就自动退出,这个对于后台管理是比较麻烦的.这个是zencart1.5在安全性上做的一个改进 ...

  9. AJAX封装(IE)

    function ajax(url,fnsucc,fnFaild){ if(window.XMLHttpRequest){ var oAjax = new XMLHttpRequest(); } el ...

  10. js的阻塞特性

    JS具有阻塞特性,当浏览器在执行js代码时,不能同时做其它事情,即<script>每次出现都会让页面等待脚本的解析和执行(不论JS是内嵌的还是外链的),JS代码执行完成后,才继续渲染页面. ...